Zyxel ZyWALL USG 50 [9/185] Zywall usg support notes

ZyWALL USG Support Notes

3. Then USG will check whether there‟s DNAT (Destination NAT) rule set, if there

is, it will translate the destination address according to the DNAT rule. If there‟s

not, USG will remain the original destination address. Usually from traffic sent

from intranet to outside, there‟s no DNAT rule set.

4. The traffic is sent to the routing procedure. USG decide where it should send the

traffic to, and via which interface.

5. The traffic is sent to the firewall processing stage. If according the firewall rule,

the traffic is allowed, USG will allow the traffic to pass, if it‟s set to Block, the

USG will drop the traffic, and generates a log if the firewall rule is set to log.

6. The traffic is sent to the ADP processing stage. USG will perform ADP checking

according to ADP rules, and ADP signatures. If the traffic is detected as anomaly

attack, the USG will block/log the traffic according to the ADP signatures.

7. The traffic is sent to the IDP processing stage. USG will perform IDP checking

according to IDP rules, and IDP signatures. If the traffic is detected as intrusion

attack, the USG will block/log the traffic according to the IDP signatures.

8. The traffic is sent to Application Patrol processing stage. USG will check the

traffic application layer to determine its class according to relative IDP signatures.

If traffic matches some application class, USG will decide how to handle the

traffic according to the App Patrol rules.

9. Traffic is sent to Content Filtering processing stage if the traffic is web traffic.

USG check what action it should take according to Content Filtering rules.

10. The traffic is sent to Anti-Virus processing stage. USG will examine the traffic

with AV signatures. If virus is detected, it will give corresponding action

according to AV setting.

11. The traffic is sent to Anti-Spam processing stage if it is mail traffic (SMTP, POP3),

then gives corresponding action according to AS settings.

12. The traffic is sent to SNAT procedure. USG will map the traffic‟s source address

according to SNAT rules (outgoing interface, customized address, NAT 1:1

address, etc, which is to be discussed later).

13. The traffic is sent to Bandwidth Management procedure. USG will allocate

bandwidth to the traffic if corresponding BWM rule is set.

14. The traffic will be fragmented if the frame is larger than the interface‟s MTU

setting.

15. The traffic is finally sent out.

1.1.2. Routing priority

Understanding Routing Priority in USG ZyWALL helps a lot for you to correctly set